Pump



0a. '24, 1944. A. w. SAY 2,361,153

PUMP

Filed Sept. 28, 1945 2 Sheets-Sheet 1 INLET ourusr O OUTLET Q uvLsr INLET OUTLET [""1 ["i 1 A V INLET ounzr f\ 3 OUTLET INLET I] 1 OUTLET must 8 INLET ourusr 12 7 l Oct. 24, 1944. A w SAY 2,361,153

PUMP I iled Sept. 28, 1943 2 SheetS -Sheet 2 :mrw

Patented Oct. 24, 1944' UNITED STATES PATENT OFFICE 2,361,153

PUMP Alan William Say, Upminster, England, assignor to The Plessey Company, Limited, Ilford, England, a British'company Application September 28, 1943, Serial No. 504,122 In Great Britain December 22, 1942 5 Claims. (01. 103--163) 1 This invention relates to improvements in or relating to pumps and has for its object to provide what may be termed a metering pump, that is to say, a pump by which small quantities of liquid can be accurately measured and supplied by means of the pump.

The invention is illustrated byway of examples in the accompanying drawings in which Fig. 1 is a cross-section of one form of pump with a single pump piston. V

Fig. 2 is a similar view at right anglesto Fig. 1.

Fig. 3 is a cross-section of apump containing four pump pistons.

Fig. 4 is a like view at right angles to Fig. 3.

Figs. 5 and 6 are details showing. alternative positioning of the ports in the casing, and Fig. 7 is a detail of a pump showing a modification of the outlet.

According to the present invention a pump comprises a, valve casing, a valve sliding axially therein, a pump recess within the valve arranged with its axis transverse to that of the valve movement and a pump piston sliding in the pump recess.

A feature of the invention, is that, the valve may be provided with two or more pump recesses each of which contains a pump piston, and the valve casing is provided with inlet and outlet ports which are alternatively placed into communication with the inlet end of the pump recesses by movements of the valve. than one pump recess and pump piston is provided, they are preferably, although not necessarily, arranged in even numbers, and the actual number of pumps may vary accordingto the size of the valve and the use for which it is required. a A further feature of the invention is that the inlet and outlet ports which lead to appropriate conduits in said casing can be varied in number, being arranged axially and spaced at suitable distances apart on opposite sides of said casing, said inlet and outlets are independent of each other, thereby providing a series of single acting pumps which can be used for supplying different kinds of fluid. or for separate distribution of a single fluid or if desired, these said conduits can be interconnected in various combinations to provide feeds of equal and/or unequal capacities or they may be interconnected to provide a single distribution, thus for example, in the case of eight pumping spaces available there can be six or eight feeds of equal capacity, or four feeds of equal capacity and two of double capacity other combinations of single or double acting pumps can be obtained by suitable interconnection of inlet and delivery ports.

Where the pump contains only one pump piston, this can be arranged as a single or as a double acting pump. In the former case inlet and outlet ports are provided in the valve casing When more and these are alternatively placed into communication with the inlet end of the pump recess by movements of the valve. By providing another pair of ports for the opposite end of the pump recess and suitably spaced axially in relation to the first named pair, the pump may be converted into a twin single acting pump or by combining the inlets and the outlets of the two sets of ports it may be constituted as a double acting pump.

A still further feature of the invention, is that means are provided for imparting reciprocating movement to the one or more pistons and valve in directions respectively at right angles to one another, for example, an eccentric or the like through the medium of a connecting rod or rods pivotally connected to the valve. In the case of a valve with one to four pumps, a single connecting rod may be used. Where only a single acting pump piston is used, the connecting rod is preferably extended beyond the pivot and is formed as a gear tooth which engages in a complementary gear slot in the pump piston. By this arrangement, movements of the valve and piston are 90 out of phase as is required for the operation of a pump of this nature.

A still further feature of the invention in the case of where there are two or more pump pistons, is that, means are provided for connecting the pump pistons to said connecting rod or rods on each side of the pivot point or points. Where there are several recesses and pump pistons, the recesses are preferably arranged in rows above and below the pivot point of the connecting rod or rods, and said valve is preferably of a rectangular shape in cross section.

If desired the valve itself can be used as either a single or double acting pump of larger capacity, suitable inlet and outlet ports being arranged in the pump casing.

Referring to Figs. 1 and 2 the valve casing I constitutes a radial cylindrical extension from a housing within which is mounted a driving shaft 2 with its axis at right angles to the axis of the valve casing l. The valve casing is machined or may be fitted with a liner M which is machined to receive within it a cylindrical valve 3 and the casing l or the casing I and liner lA are provided with inlet and outlet ports 4, 5 at opposite ends of a diameter of the casing, these ports leading to appropriate conduits 4A, 5A.

An eccentric 6 formed on the driving shaft 2 is connected by means of a strap 1 to the valve 3 to which the connecting rod 1 is pivoted at 8 d ey d the pivot the connecting rod is continued in an extension formed as above stated of involute or cycloidal tooth form 9.

Within the valve 3 there is a cylindrical recess ill, the axis of which as sh'ownin Figs. 1 and 2 is at right angles both to the axis of the valve casing I and to the axis of the driving shaft 2 and this recess I constitutes a pump barrel open at its opposite ends in the side wall of the valve 3. A pump piston II slidably mounted in the recess III has its opposite ends curved to conform to the cylindrical curvature of the valve 3 so that the piston II may be moved at each end of its stroke to a position at which substantially zero clearance remains between it and the valve casing I so that the unswept volume of the pump is reduced to a minimum.

The gear tooth end portion 9 of the strap I is preferably truncated to fit substantially into the base of the tooth space which serves more effectively to guide the piston II and to prevent any rolling thereof around its axis.

As has before stated, the two sets of inlet and outlet conduits 4A, A may be used separately thus obtaining the benefit of two independent single acting pumps from the one pump piston H; although as an alternative the two inlets 4 and outlets 5 respectively may be interconnected to a single distribution line to provide a, double acting pump.

In operation the eccentric 2 is rotating anticlockwise and is shown in the bottom dead centre position. In this position the lower ports 4 and 5 are uncovered and the piston II is moving to the left so causing fiuid to be discharged from the left hand pumping space through delivery port 5, and drawn into the right hand pumping space through the inlet port 4.

After 90 further rotation the piston II has reached the end of its stroke (the fluid being completely discharged from the left hand pumping space, and the right hand pumping space being completel filled), and the valve 3 has risen to a point between the upper and lower ports so that there is no communication between these ports and the pumping spaces.

Further rotation of the eccentric brings the pumping spaces into communication with the upper ports and the piston I I starts moving to the right so drawing fiuid through the upper port 4, and discharging fluid through the upper port 5.

The cycle is then repeated.

It will be seen that this arrangement provides two separate deliveries.

Referring to Figs. 3 and 4 the valve casing I provides a housing for the driving shaft 2, valve 3 inlet and outlet ports, 4, 5 conduits 4A, 5A eccentric 6 and strap 1 pivoted at 8 to the valve 3 as herein described with reference to Figs. 1 and 2.

In this arrangement the valve 3 is of a rectangular shape and contains four transverse recesses I2, each of which serve as a pump barrel and provided with a slidable pump piston I3 therein.

The connecting rod I is extended beyond the pivot B and has fixed thereto transverse pins I4 above and below the said pivot 8 on either side of the connecting rod I; the respective outer ends of these pins I4 fit into a slot I5 arranged midway in each pump piston I3 whereby on rotation of the eccentric 6 a reciprocating motion is imparted to the pump pistons I3; the slots I5 allow the necessary relative movement between the pistons I3 and pins I4 and said motion of eccen-- by closing one of the upper pumping spaces, or in the case where there are a plurality of pump pistons above the pivot point of the connecting rod closing a pumping space in the respective upper pumping recesses, and said one or more closed spaces each communicate by way of a duct I6 in the valve 3 with the upper part of the valve chamber housing; the closed recess forming a guide for the pump piston. Inthe case where there are two inlet ports on one side of the casing the closed pumping space is arranged adjacent thereto.

If desired the respective closed pumping space or spaces may be arranged at the lower portion of the valve, in which case they each communicate through a duct in the valve with the base of the pump casing.

The left hand upper pumping spaces are blanked off at their outer ends and are merely vented to the central chamber of the pump so that these pumping spaces are ineffective. In this way six feeds are provided, one pair on the left hand side and two pairs'on the right.

The cycle for each individual piston is simi lar to that described with reference to Figs. 1 and 2, but in this case four pistons are operated from a single connecting rod, one pair of pistons operated by pins I4 arranged transversely to the connecting rod I above the pivot point and the other pair of pistons I3 are operated by pins I4 below the point at which the connecting rod is pivoted to the valve 3.

Figs. 5 and 6 show two further arrangements of the inlet and outlet ports, in Fig. 5 there are three inlet and three outlet ports the outlet on the left hand side of the illustration having twice the output of those on the right hand side and in Fig. 6 four inlet and four outlet ports of equal capacity as indicated.

The valve itself may be utilised as a piston to provide a boost for the inlet pressure to the pump and if only one face of the valve is used for this purpose as a single acting boost pump it will be convenient to take the pressure from that pump into an accumulator from which the liquid under pressure can be delivered to the pump inlet or inlets. On the other hand, both ends of the valve may be used to afford a double acting boost pump by employing the interior of the casing within which the driving shaft is situated to constitute a boosting pump chamber to co-operate with the opposite end of the valve.

In Figs. 5 and 6 the two pistons are operated from a single connecting rod, one being operated by pins above and the other being operated by pins below the point at which the single connecting rod is pivoted on the sliding valve member. In Fig. 5 the delivery ports shown on the left handside are combined, thus providing three feeds one of which has twice the capacity of the other two. In Fig. 6 the ports are proportionally increased in number so that this arrangement provides four separate deliveries.

Referring to Fig. 7 the parts and reference numerals are identical with Figs. 4 and 5 with the exception of the outlet feed; in this modification the outlet ports I! and passageways I8 leading thereto are interconnected with a single conduit I9 thereby providing a feed of double capacity.

The arrangement and operation shown in Fig. '7 is similar to that shown in Fig. 4 but in which the two right hand delivery ports are combined to provide a single distribution havin twice the capacity of that on the left hand side of Fig. 7.

As a further alternative, the same driving shaft and eccentric can be utilised to operate a second single acting boost pump diametrically opposed to the valve or the whole apparatus may be duplicated by providing a diametrically disposed connecting rod, both ends of which operate a combined pump and valve of which the pump may be used either as a single acting or as a double acting device, and the valve may be utilised either as a single or double acting boost pump.

In fact the invention is not necessarily limited to a mere duplication of the parts as three or more sets of parts may be employed each providing the valve and pump in any of the combinations above described.

ing, at least one connecting rod pivotally connecting said valve to the eccentric, said rod provided with an extension beyond the pivot point and at least one intermediate member operatively connected to said connecting rod and each piston which are driven at right angles to the movement of the valve.

3. A pump comprising a valve casing provided with inlet and outlet ports arranged at diametrically opposite positions, a valve containing a plurality of pump recesses transversely arranged The invention is not limited moreover to the method described for operating the pump piston. For instance, the connecting rod could be engaged either on one or on both sides of the pump piston between laterall projecting ears or in lateral slots provided on one or on opposite sides of the piston respectively, the portion of the connecting rod located between those cars or recesses being of cylindrical form.

I claim:

1. A pump comprising a valve casing provided with inlet and outlet ports arranged at diametrically opposite positions, a valve provided with at least one recess transversely arranged to the axial movement of said valve reciprocating within said casing, a pump piston contained in each recess in said valve, an eccentric housed within an extension provided in said valve casing, and a connecting rod driven by said eccentric pivotally connected to said valve, said rod provided with an extension beyond the pivot point and engaging with at least one piston.

2. A pump comprising a valve casing provided with inlet and outlet ports arranged at diametrically opposite positions, a valve containing a plurality of pump recesses transversely arranged to the axial movement of the valve reciprocating within said valve casing, a pump piston sliding in each pump recess in said valve, an eccentric housed within an extension formed in said casto the axial movement of the valve reciprocating within said casing, a pump piston sliding in each pump recess in said valve, an eccentric, at least one connecting rod pivotally connecting said valve to the eccentric, and operatively connected to said pump pistons actuating both the pump pistons and valve in directions respectively at right angles to one another at out of phase.

4. A pump comprising a valve casing provided with inlet and outlet ports therein, a valve with a pump recess transversely arranged to the axial movement of said valve moving within said valve casing, a pump piston with a slot at its centre sliding in said pump recess, an eccentric, a connecting rod pivotally connecting said valve to the eccentric, said connecting rod provided with a tooth beyond the pivot point which engages with the complementary slot in said pump piston.

5. A pump comprising a valve casing provided with inlet and outlet ports arranged at diametrically opposite positions, a valve containing a plurality of pump recesses transversely arranged to the axial movement of the valve reciprocating within said casing, a pump piston sliding in each pump recess in said valve, an eccentric, at least one connecting rod pivotally connecting said valve to the eccentric, and means for connecting the respective pump pistons to the connecting rod on each side of the pivot point thereof, the arrangement being such that said pump pistons and valve are reciprocated in directions respectively at right angles to one another at 90 out of phase.

ALAN WILLIAM SAY. 

